Medium

Authenticated TKEY query denial of service in ISC BIND 9 named

IdentifiersCVE-2026-3119CWE-20

CVE-2026-3119 is a denial-of-service vulnerability in ISC BIND 9 where the named daemon may terminate unexpectedly while processing a correctly signed query containing a TKEY record. The vulnerable code path is only reachable when the incoming request carries a valid TSIG transaction signature generated with a key that is declared in the named configuration. According to the provided advisory data, affected versions are BIND 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9.18.x and 9.18.x-S1 are explicitly stated to be unaffected.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

A successful exploit causes the named process to crash or terminate unexpectedly, resulting in denial of service for DNS resolution and/or authoritative DNS service provided by the affected instance until the daemon is restarted or service is otherwise restored. Based on the provided information, the impact described is service disruption rather than code execution or privilege escalation.

Mitigation

If you can’t patch tonight, do this now.

Limit which clients can send TSIG-authenticated requests using configured keys, and restrict exposure of interfaces or services that accept such authenticated queries to only trusted management peers. Review TSIG key configuration and remove unused trusted keys where possible. These measures may reduce exposure, but the definitive mitigation is to apply the vendor patch.

Remediation

Patch, then assume compromise.

Upgrade to a fixed BIND 9 release. The provided content indicates ISC released patched versions including BIND 9.20.21 and 9.21.20, and downstream packaging notes reference bind9 1:9.20.21-1~deb13u1 for Debian trixie. Use the vendor-provided fixed release appropriate for the deployed branch and Supported Preview Edition build.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

Internet Systems ConsortiumBindapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

10 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

10 SOURCESView more in app

ca ccsNews

Mar 25, 2026

ISC BIND security advisory (AV26-280) - Canadian Centre for Cyber Security

A vulnerability in ISC BIND 9 where an authenticated query containing a TKEY record may cause the named process to terminate unexpectedly.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity8